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Radio-frequency (RF) plasma etching of graphite with oxygen: a scanning tunnelling microscope study
A286 Surface Science 284 (1993) 263-272 North-Holland
Radio-frequency (RF) plasma etching of graphite with oxygen: a scanning tunnelling microscope study Hong-Xing You, Norman M.D. Brown * and Khalid F. AI-Assadi Surface Science Laboratory, Department of Applied Physical Sciences, University of Ulster, Coleraine, Co. Londonderry, BT52 ISA, Northern Ireland, UK Received t September 1992; accepted for publication 17 November 1992 The surface topography of highly oriented pyrolytic graphite (HOPG) after exposure to a radio-frequency (RF) oxygen plasma has been studied using scanning tunnelling microscopy (STM) in ambient air. The STM images obtained show that the HOPG surface after etching in an oxygen RF plasma is remarkably different from that of the freshly cleaved material. The resultant topographical features are found to be strongly dependent on the etching conditions used. The layer-by-layer etching of graphite by an oxygen RF plasma revealed in the high resolution STM images obtained is attributed to the structural characteristics of graphite and to the synergistic effects of oxygen ion bombardment and atomic oxygen reactions.
Surface Science 284 (1993) 273-280 North-Holland
The interaction of potassium submonolayers adsorbed on Pt(111) with oxygen and the adsorption of ethylene on the resulting modified surfaces: a TDS and UPS study A. Cassuto *, S. Schmidt and Mane Mane Laboratoire Maurice Letort, CNRS, 405 rue de Vandoeuvre, 54600-1Pdters-I~s-Nancy, France Received 1 September 1992; accepted for publication 16 November 1992 UPS shows that K atoms deposited on Pt(lll) in the submonolayer range strongly interact with oxygen molecules. At 300 K, oxygen molecules dissociate. Oxygen atoms either attach to potassium atoms or lead to K20. At 95 K, depending on the experimental conditions (exposure and pressure), potassium peroxide or potassium superoxide, as majority species, form. TDS as well as UPS indicate that on these surfaces ethylene is ~--bonded as on Pt(lll) surfaces, partially covered with K atoms. No ethylene adsorption occurs on surfaces fully covered with oxygen atoms or oxides. EthYlene adsorption therefore occurs on the clean part of the sample and is disturbed by the presence of various species of potassium attached to oxygen.
Surface Science 284 (1993) 281-290 North-Holland
Spectroscopy and reactions of hydr~oic acid on silicon single crystal surfaces III. H N 3 and D N 3 on S i ( l l l ) ( 7 x 7)
Jason C.S. Chu, Y. Bu and M.C. Lin Department of Chemistry, Emory University,Atlanta, GA 30322, USA Received 18 September 1992; accepted for publication 17 November 1992 We have studied the thermal stability and spectroscopy of HN 3 on Si(lll)(7 × 7) in the temperature range from 120 to 1350 K. The results are similar to those observed on other two low-index Si surfaces. HN 3 was found to ~ i a r l y adsorb on Si(111)(7 x 7) at 120 K, with the formation of dimers at higher dosages (~ 2.0 L). At 270 K, HN 3 began to decompose into HN and
Radio-frequency (RF) plasma etching of graphite with oxygen: a scanning tunnelling microscope study Hong-Xing You, Norman M.D. Brown * and Khalid F. AI-Assadi Surface Science Laboratory, Department of Applied Physical Sciences, University of Ulster, Coleraine, Co. Londonderry, BT52 ISA, Northern Ireland, UK Received t September 1992; accepted for publication 17 November 1992 The surface topography of highly oriented pyrolytic graphite (HOPG) after exposure to a radio-frequency (RF) oxygen plasma has been studied using scanning tunnelling microscopy (STM) in ambient air. The STM images obtained show that the HOPG surface after etching in an oxygen RF plasma is remarkably different from that of the freshly cleaved material. The resultant topographical features are found to be strongly dependent on the etching conditions used. The layer-by-layer etching of graphite by an oxygen RF plasma revealed in the high resolution STM images obtained is attributed to the structural characteristics of graphite and to the synergistic effects of oxygen ion bombardment and atomic oxygen reactions.
Surface Science 284 (1993) 273-280 North-Holland
The interaction of potassium submonolayers adsorbed on Pt(111) with oxygen and the adsorption of ethylene on the resulting modified surfaces: a TDS and UPS study A. Cassuto *, S. Schmidt and Mane Mane Laboratoire Maurice Letort, CNRS, 405 rue de Vandoeuvre, 54600-1Pdters-I~s-Nancy, France Received 1 September 1992; accepted for publication 16 November 1992 UPS shows that K atoms deposited on Pt(lll) in the submonolayer range strongly interact with oxygen molecules. At 300 K, oxygen molecules dissociate. Oxygen atoms either attach to potassium atoms or lead to K20. At 95 K, depending on the experimental conditions (exposure and pressure), potassium peroxide or potassium superoxide, as majority species, form. TDS as well as UPS indicate that on these surfaces ethylene is ~--bonded as on Pt(lll) surfaces, partially covered with K atoms. No ethylene adsorption occurs on surfaces fully covered with oxygen atoms or oxides. EthYlene adsorption therefore occurs on the clean part of the sample and is disturbed by the presence of various species of potassium attached to oxygen.
Surface Science 284 (1993) 281-290 North-Holland
Spectroscopy and reactions of hydr~oic acid on silicon single crystal surfaces III. H N 3 and D N 3 on S i ( l l l ) ( 7 x 7)
Jason C.S. Chu, Y. Bu and M.C. Lin Department of Chemistry, Emory University,Atlanta, GA 30322, USA Received 18 September 1992; accepted for publication 17 November 1992 We have studied the thermal stability and spectroscopy of HN 3 on Si(lll)(7 × 7) in the temperature range from 120 to 1350 K. The results are similar to those observed on other two low-index Si surfaces. HN 3 was found to ~ i a r l y adsorb on Si(111)(7 x 7) at 120 K, with the formation of dimers at higher dosages (~ 2.0 L). At 270 K, HN 3 began to decompose into HN and